pics wanted for cutting the head

[Harry]

Hi Have a look at these photos of when I machined my head. I used an old spark plug with the hex machined off. Can not recall lathe speed?

[Diggs345]

Originally Posted by Harry

Hi Have a look at these photos of when I machined my head. I used an old spark plug with the hex machined off. Can not recall lathe speed?

Nice one , how did you machine the bowl out ?

[HenrikSchmidt]

It does not need to be spinning really fast.
i woud say 4-500rpm should be fast enough, you're never gonna meet the cutting speed of your tool anyway

you will not have any problems with the balance at that speed..
you need to make sure that the head is running true before cutting, not for the balance, but for the precision of your head..

[hannesd]

Originally Posted by Harry

Hi Have a look at these photos of when I machined my head. I used an old spark plug with the hex machined off. Can not recall lathe speed?

and the rubber bands around the head go there for reduction of the sharp noise,right?
allso, did you use the spark plug with or without the washer between the spark plug and the head?

did you do that on a manual lathe?

thanks allready

Hannes.

[Harry]

Correct the rubber bands are to stop it 'chattering' I left the bowl and took 1mm off the mating surface. I am not 100% sure but I think I removed the plug washer.

[(F5)]

Originally Posted by Harry

Correct the rubber bands are to stop it 'chattering' . . .

You what? How does that work? (I'm self taught, read badly, as my tutor was a muppet)

[wrench]

Originally Posted by (F5)

You what? How does that work? (I'm self taught, read badly, as my tutor was a muppet)

"chattering" is caused by excessive vibration, a by product of the machining/cutting process and causes an annoying noise. If you get too much vibration you will get an extremely rough and uneven depth cut pattern.

The rubber bands act as a damper and "absorb" the vibration.

[hannesd]

Originally Posted by Harry

Correct the rubber bands are to stop it 'chattering' I left the bowl and took 1mm off the mating surface. I am not 100% sure but I think I removed the plug washer.

was that off an ec 200/250 or 300, you cut 1mm?
i'm curious as to what difference it might make.
i'd like to do it properly as to get the most out of my 200,but have some doubts to cutting the bowl with probably a manual lathe, def not CNC...

Hannes.

[Diggs345]

Its not just a case of turning 1mm off , you need to do a solder test on the squish band to find out the correct amount to remove, you also need to correct the head volume to keep the compression ratio right .

[hannesd]

Originally Posted by Diggs345

Its not just a case of turning 1mm off , you need to do a solder test on the squish band to find out the correct amount to remove, you also need to correct the head volume to keep the compression ratio right .

yes i realize,but if it's too hard to shape the bowl on a manual lathe,i'd go the lazy way and just measure the squish now and make sure not to shave the head too much so compression would go skyhigh.
i could get it done by a pro, you'll say, yes true, but therefor i'd have to find one in the area, wich i have no clue to.
plus most of all i'm a do it all yourself kinda guy, so id be more satisfied if i could achieve improvement if i did it myself.
some of you will understand my vision, others will say, don't bother trying

thanks for all the input so far ,

ciao Hannes.